Effect of the timing of sodium acetate infusion on the daily rhythms of milk synthesis and plasma metabolites and hormones in Holstein cows

Abstract

Dairy cows have a daily pattern of feed intake which influences ruminal fermentation and nutrient absorption. Milk synthesis also exhibits a daily rhythm and is altered by the timing of feed availability. Nutrients can regulate physiological rhythms, but it is unclear which specific nutrients affect the rhythms of milk synthesis in the cow. The objective of this study was to determine the effect of the timing of acetate infusion on the daily rhythms of feed intake, milk synthesis, milk fatty acids, plasma insulin and metabolites, and core body temperature. Ten lactating ruminally cannulated Holstein cows (127 ± 24.6 d in milk; mean ± standard deviation) were arranged in a 3 × 3 Latin square design. Treatments were ruminal infusions of 600 g/d of acetate either continuously throughout the day (CON) or over 8 h/d during the day (day treatment, DT; 0900 to 1700 h) or the night (night treatment, NT; 2100 to 0500 h). Experimental periods were 14 d with a 7-d washout between periods. Cows were milked every 6 h during the final 7 d of each experimental period to determine the daily pattern of milk synthesis. Blood samples were taken to represent every 4 h across the day and plasma glucose, insulin, β-hydroxybutyrate, urea nitrogen, and acetate concentration were measured. An intravaginal temperature logger was used to measure core body temperature. Data were analyzed with cosinor-based rhythmometry to test the fit of a cosine function with a period of 24 h and to determine the acrophase (time at peak) and amplitude (peak to mean) of each rhythm. Milk yield fit a daily rhythm for all treatments and DT and NT phase-delayed the rhythm and DT increased the robustness of the rhythm. Milk protein concentration fit a daily rhythm for all treatments and DT increased robustness, whereas NT phase-delayed the rhythm. Plasma acetate concentration also fit a daily rhythm in all treatments. Plasma acetate peaked at ~1600 h in CON and DT and at 0053 h in NT, reflecting the timing of treatment infusions. There was a daily rhythm in plasma β-hydroxybutyrate that reflected the plasma acetate rhythm. Core body temperature fit a rhythm for all treatments, but the amplitude of the rhythm was smaller than previously observed. In conclusion, the timing of acetate infusion influences peripheral rhythms of milk synthesis and plasma metabolites.

Effects of an Hourly Bolus Postruminal Infusion of Flaxseed Oil or Palm Oil on Circulating Fatty Acid Concentrations and Hepatic Expression of Pyruvate Carboxylase and Phosphoenolpyruvate Carboxykinase in Dairy Cattle

“…The current experiment utilized an in vivo model, where SCFA and triglyceride products were bolus-dosed hourly over a period of 8 h. Previously, we showed that the infusion of propionate, compared with glucose infusion, maintained PCK1 levels in the bovine liver but was not different from the infusion of water [17], and the effects of propionate were through counteracting the effects of elevated insulin concentrations. Although plasma insulin was not measured in the current experiments, the infusion of acetate to match the energy supply would not be expected to result in elevated plasma insulin [41]. Therefore, it is not surprising that there is a lack of effect of SCFA treatment on PCK1 expression.…”

Higher Concentration of Dietary Selenium, Zinc, and Copper Complex Reduces Heat Stress-Associated Oxidative Stress and Metabolic Alteration in the Blood of Holstein and Jersey Steers

“…A feeding trail of 20 days was conducted in each period, and blood samples were collected on the last day. A 7-day washing period was maintained between each Latin square to return the mineral concentration as baseline level [ 32 , 33 , 34 ]. The ingredients and chemical compositions of the basal TMR are presented in Table 1 .…”

Importance of circadian rhythms in dairy nutrition

“…Daily milk fat yield and average milk fat and protein concentration were not changed, but the rhythms of milk yield and milk fat and protein concentration were nearly inverted and the amplitudes of the rhythms were also modified. Restricted feeding modifies energy and all nutrients, so follow-up experiments were conducted that ruminally infused acetate and duodenally infused casein either continuously or for 7 h during the day or the night (Matamoros et al 2022;Salfer et al 2023). The timing of both protein and acetate infusion modified the daily pattern of milk synthesis.…”